Method for preparing disodium ethylene glycol bis(2-ethyl-1-butyl)sulfosuccinate

The invention discloses a method for preparing disodium ethylene glycol bis(2-ethyl-1-butyl)sulfosuccinate. The method comprises the following steps of: combining maleic anhydride and two hydroxyl radicals on ethylene glycol to perform mono-esterification to obtain ethylene glycol bis(monomaleate); performing di-esterification on the ethylene glycol bis(monomaleate) and 2-ethyl-1-butanol to obtain ethylene glycol bis(2-ethyl-1-butyl) dimaleate; and performing conjugate addition on the ethylene glycol bis(2-ethyl-1-butyl) dimaleate and sodium hydrogensulfite to obtain the product, wherein whenthe maleic anhydride is reacted with the ethylene glycol, a carbon-based solid acid catalyst is adopted. The method is simple, and easy to implement; the consumption of raw materials is reduced; the cost is saved, and impurities of the product are reduced.